Condition Monitoring and Performance Evaluation of Power Transformers Solid Insulating Materials Based on Operational Stresses
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Power transformers are vital parts of electric energy transmission and generation systems. This article evaluates the causes of solid insulating dielectric degradation in power transformers based on operational stresses. Dissipation Factor (DF) or tan delta (Tan and power factor (PF) tests was conducted on the transformer windings based on the guard-to-ground-to-shield (GST) method using the Delta-3000 Megger instrument to measure winding capacitance (PF), leakage current, and Tan values. Findings revealed that there were large, sudden increases in variations in the winding capacitance values ranges from 2954 to 9638 and tan values from 0.9976 % to 1.241% measured after failure at 40 when compared to base value capacitance from 2569 to 8381 and tan values from 0.344 % to 0.428% measured at 30 before transformer failure. These higher changes in tan overtime, capacitance (PF), and leakage current indicated deteriorating insulating material conditions, contaminations, dielectric losses and degradation. Also, thermal stress caused mechanical deterioration with time at an elevated temperature and degradation; Mechanical stress caused transient currents during switching on power transformer, damaged insulation due to mechanical vibration; Electrical stresses create significant high-voltage exposure to voltage transients; and Environmental stresses results due to presence of moisture, dirt, chemicals, radiation, or other contaminants. The proposed Condition monitoring can be used to monitor transformers parameters such as dissolving gas analysis, partial discharge, oil quality, vibration, moisture, windings temperatures, detect faults at incipient stage; avoid catastrophic events; Optimized maintenance and prevent failures.
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Amol Nikam and Arun Thorat. Condition Monitoring of Power Transformer: A Practical Approach. International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181. Vol. 10 Issue 05, May-2021 www.ijert.org
ANSI/IEEE C57.115-2011. Guide for Loading Mineral-Oil-Immersed Power Transformers up to and Including 100 MV A with 55°C or 65 °C Average Winding Rise
E.P. Dick and E.P.Erwin, (2018) “Transformer diagnostic testing by frequency response analysis”. IEEE Transactions on Power Apparatus and Systems.
IEC 60851-3(2021) International Standards Part 3 for Mechanical and Electrical properties tests.
IEEE Standard 1-2000. “IEEE Recommended practice – General principles for temperature limits in the rating of electrical equipment and for the evaluation electrical insulation 2000.
Ivan V. Bryakin, Igor V. Bochkarev, Vadim R. Khramshin, Vadim R. Gasiyarov and Ivan V. Liubimov. Power Transformer Condition Monitoring Based on Evaluating Oil Proper ties. Machines 2022 10,630. https://doi.org/10.3390/machines10080630
Kim, Y.; Park, T.; Kim, S.; Kwak, N.; Kweon, D. Artificial Intelligent Fault Diagnostic Method for Power Transformers using a New Classification System of Faults. J. Electr. Eng. Technol. 2019, 14, 825–831.
L.Pettersson, N.L. Fantana, and U. Sunderman. “Assessment ranking of Power Transformers Using Condition Based Evaluation. A New Approach” CIGRE Paris Conference Paper 2018.
Nguyen, T. T. "Constrained Optimization Procedure for Evaluating Cyclic Loading of Power Transformers." lEE Proceeding’s, Generation, Transmission and Distribution 2005
Norghen. W. “Power Factor and Capacitance Measurement of Transformer Core Insulation”, Proceedings of the Annual International Conferences of Doble Clients 2019.
Pravin Rathod, Ankit Shah Patel, Sameer Patel, and Chirag Parekh. (2016) “Condition Monitoring of Power Transformer Using Different Techniques” STM Journals Trends in Electrical Engineering, ISSN: 2249-4774 Volume 6, Issue 2. www.stmjournals.com
Ravindra Arora and Bharat Singh Rajpurohit (2019) “Solid and Liquid Insulating Materials, Their Classification, Properties and Breakdown” Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India.
Ravindra Arora, and Wolfgang Mosch. High Voltage and Electrical Insulation Engineering, 2nd Edition ISBN: 978-1- 119-56887-2 March 2022 Wiley-IEEE Press
Rickley, A. L. “Transformer Insulation Power Factors, A Progress Report”, Proceedings of the Annual International Conferences of Doble Clients 2018.
Šimková, M.; Ministr, M.; and Hammer, M. Expert Systems in Transformer Diagnostics.in Recent Advances in Mechatronics; Springer: Berlin/Heidelberg, Germany, 2010; pp. 145–150.
Singh, R.P; Sonawane, A.V.; Satpute, M.S.; Shirsath, D.Y; Thakre, M.A. Review on Traditional Methods of Condition Monitoring of Transformer. In Proceedings of the International Conference on Electronics and Sustainable Communication Systems (ICESC), Coimbatore, India, 2–4 July 2020; pp. 1144–1152.
Theodore Wildi, (2014).“Electrical Machines, Drives, and Power Systems” Sixth Edition, Publisher Pearson Education Limited Edinburgh Gate Harlow Essex CM20 2JE
W.J. McNutt. "Risk Assessment for Loading Transformer beyond Name-plate ra ting” Proceeding of American Power Conference 2019.
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